Method of and apparatus for attaching clinch nuts to sheet metal members



p 22, 1953 L. MUCHY 2,652,942

METHOD OF AND APPARATUS FOR ATTACHING CLINCH NUTS TO SHEET METAL MEMBERS Filed July 2, 1949 5 Sheets-Sheet l ET] A x fw lnventor Sept. 22, 1953 Y L. MUCHY 2,652,942

METHOD OF AND APPARATUS FOR ATTACHING CLINCH NUTS TO SHEET METAL MEMBERS Filed July 2, 1949 5 Sheets-Sheet 2 ggy-Mk Sept. 22, 1953 1.. MUCHY METHOD OF AND APPARATUS FOR ATTACHING CLINCH NUTS TO SHEET METAL MEMBERS Filed July 2, 1949 5 Sheets-Sheet 5 Bnvcntor u WWW fF E Sept. 22, 1953 MUCHY 2,652,942

METHOD OF AND APPARATUS FOR ATTACHING CLINCH NUTS TO SHEET METAL MEMBERS Filed July 2, 1949 5 Sheets-Sheet 4 3nvcntor Sept. 22, 1953 MUCHY METHOD OF AND APPARATUS FOR ATTACHING CLINCH NUTS TO SHEET METAL. MEMBERS 5 Sheets-Sheet 5 Filed July 2, 1949 Zhwentor Bu [51/21 W7) (lttornegs Patented Sept. 22, 195 3 Frisian ME HOD OF AND APPARATUS FOR ATTACH- ING CLINCH NUTS TO 1 MEMBERS SHEET METAL I Louis Muchy; Detroit, Mich., assignor to General Mot'o'rs Corporation, Detroit,- Mich, a corporation of Delaware Application July 2, 194.9,Serial No. 102,828

I 12 Claims. 1

This invention relates to a method. of and apparatus for attaching clinch nuts to'sheet metal members.

The common practiceinattachingclinch nuts to sheet metal membershas been tofirst punch holes of the desired shape and size in the members on an ordinary punch press, then insert the clinch nuts into the holes eithermanuallyor by a feeding and insertingmachine,v and finally to place the sheet metal. member in another machine where portions of the nuts are staked over or otherwise deformed tohcause the nuts to become clinched in, place on the "sheet metal member. This not onlyfirequires considerable labor ecause of the several operations involvedand the necessary handling of the clinch nuts and the metal sheets incident thereto, butalso presents the problems of having to frequently sharpen or replace the die whichservesto punch the holes in the sheet metal member to receive the clinch nuts, and the difiicultyrin holding the size of the holes within the necessarylimits to insure that th clinch nuts will fit properly in them.

My invention eliminates these objections by making it possible to quickly performvv all of the operations incident to the attachment vof the clinch nuts in a single machine. ,Also, byarranging this machine so, that each clinch nut will serve as a die to punch its own hole in the sheet metal member towhichit is to be attached, and will remain in the hole it has punched, not only is the sharpening. or replacement of dies eliminated, but there is considerable saving of labor in handling and assembling operations. A further saving is effected by causing the nuts to become staked or clinchedin place in the sheet metal members immediately following the hole punching operation, simplyby rotating a part of the machine a quarter of a revolution and then bringing it into contact with the nut. whereby the corners of the'latter will be expanded or staked over to engage thesheetmetal member to hold the nut in place in the hole therein.

Other objects and advantages of the invention will become apparent upon reference to the specification and accompanying drawings, in which Figure l is a fragmentary elevational view of a machine embodyingtheinvention.

Figure 2 is a vertical sectional View, on a larger scale, through the upper portion of the machine shown in Figure 1.

Figure 3 is a fragmentary perspective view, showing a sheet metal member with a clinch nut in position in a hole it has punched therein, 10- catedover a portion of --the.machine which has cooperated in the punching; operation, and will serve in the next operation to -01inch the nut in place.

Figure sis a vertical sectional view, through the lower portion of thebmachine shown-in Figure 1.

Figure 5 isa sectional view, taken on the line 5-5 of Figure 4.

Figure 6 is a fragmentary vertical sectional view through a portion of themachine.

Figure 7 is a fragmentary developed view of part of the structure shown in Figure 6.

Figure 8 is an enlarged elevational view of the clinch nut feeding'mechanism.

Figure 9 isa sectionalview, taken on the line 9- of Fig. 8.

Figure 10 is a perspective view of a portion of the mechanism shown in Figure 8.

Figure 11 is a fragmentary perspective view of a clinch nut mounted in a hole in a sheet metal member, in inverted position to show how the nut appears after it has been clinched in place.

Figure 12 is a diagrammatic view showing the hydraulic cylinders which operate portions of the machine, the valves for controlling the operation of such cylinders, and the piping therebetween.

Figure 13 is a wiring diagram showing the electrical apparatus which actuates the valves and thereby controls the sequence of operations of the machine.

ihe form of clinch nut used with my invention is shown in Figure 3, the nut being designated generally by the letter N, and consisting of a body portion 2 which is of substantially square form in cross-section, and having flanges t projecting outwardly from two of its opposite sides. A threaded hole 6 extends through the nut. The sheet metal to which the clinch nut is to be attached is designated by the letter S.

In Figure 1, there is shown a general view of the machine which serves to attach the clinch nuts to the sheet metal. It consists of a base 8 and frame It, there being spaced stationary supporting members l2, it and It extending horizontally from the frame. Referring to Figure 4, ii; is a cylinder end member having a threaded portion it received in a hole'in the base, and 22 is a cylinder which is connected to the end memher by bolts 24. A piston 26 having a rod 23 extending upwardly therefrom, is mounted within the cylinder. The upper end of the piston rod is threaded at St to receive the base 32 of a female die member 3t which is slidably supported for vertical reciprocatory movement in a stripper collar 35 which is secured to the support member 82.

The die member has a square hole 38 formed in it, and the upper edgeis ground away at an angle, as at it to. provide shearing edges d2 aroundthe hole-3B. The lower end of the latter communicates with a larger central bore le formed within the die, there being a discharge opening it formed in the wall of the die at one side thereof. 48 is a plug secured in the bore of the die by set screw. 55, the plug having an inclined-facev 52 whichdirects slugs dropping into the bore out through the discharge opening 46, there being a relatively large hole 54 formed in the support member around the die to permit the slugs to drop downwardly out of the machine.

Referring now to Figure 2, a cylinder end member 55 is secured to support I6 by a portion 58 which is threaded thereinto. A cylinder 60 is secured to end member 56 by screws 62. His a piston located within the cylinder 60 and having a rod 38 extending downwardly therefrom, the lower end portion 68 being of reduced diameter and having a plurality of flats 16 provided thereon. Secured to end portion 68 by set screws I2, which bear on one of the flats 1B, is a punch member l t, the lower end 16 of which is of reduced diameter, and has secured within it a bushing 18 formed of non-ferrous material, the bushing and the lower end I6 of the punch member being cut away at one side thereof, as indicated at 80, for a purpose to be hereinafter described. 82 is a permanent magnet, formed of any suitable material, which is mounted within the bushing I8, the upper end of the magnet seating against the punch member 14,

Secured to the lower end of the cylinder 69 by screws 84 is an adapter 88 to which a plate 88 is fastened by screws 90. A spacer member 92 is connected to the plate 88 in any suitable manner, and secured on opposite sides of the spacer member by bolts 94 are a pair of side plates 96. A chute 93 is clamped between these side plates, and leads upwardly to an overhead hopper (not shown) of any suitable type which is adapted to feed the clinch nuts in proper position into the chute. As shown in Figure 9, the chute is of inverted U-shape in cross-section, being provided with grooves I80 at each side, into which grooves the flanges i of the clinch nuts N fit sufiicient loosely so that the nuts may freely slide downwardly in the chute, the body portion 2 of the nuts projecting downwardly through a slot I82 in the lower face of the chute.

Mechanism for advancing the clinch nuts in the chute and feeding them one at a time to the punch is shown in Figures 8-10. This consists of a forked member I84 which is pivotally supported between the side plates by a trunnion portion I06 each end of which fits into an opening it, shown in Figure 1, formed in each of the plates. Located between the plates immediately beneath the forks of the member I8 3 which are bevelled as at Ht, is a slide H2 provided with tongues IM which fit freely within grooves H6 which are formed in the side plates. A compression spring II8 supported on a pin I28 has one end extending within a hole I22 formed in the slide, that end of the spring bearing against the bottom of the hole and the other end bearing against the head I24 of the pin, which in tur bears against an arm I26 depending from the member I04, the effect of the spring being to tend to move the slide II'Z toward the left, as viewed in Figures 8 and 10.

The slide I52 is moved in the opposite direction by a lever I28, which is pivoted on pin I38 supported in side plates 56, the lever being provided with arms I32 and I34. The free end of the arm I32 bears against a projection I36 which extends upwardly from the slide II2 between the forks of member N14. The free end of arm I34 fits within a slot I38 formed in the punch member is, so that as the latter moves downwardly, the lever rocks about the pivot pin I38 and the arm I32 bearing against the projection I36 causes the slide II2 to move to the right as viewed in Figures 8 and 10, during which movement it causes the spring II8 to become compressed.

The punch member I4 is provided with a projection i IDwhich has a finished face portion M2 at each side, which face portions bear against the inner surfaces of the side plates 96 during the up and down'movement of the punch member to prevent rotation of the latter.

The slide I I2 has a vertically extending slot HM formed through it, and mounted in this slot is a pusher hi6 which is adapted to slide up and down in the slot. The lower end of the pusher extends downwardly through an elongated slot M8 formed in the top of the chute 9%, and is cut angularly to form a pointed edge I53 which is adapted to engage the side edge of the nut N which happens to lie immediately beneath it, as shown in Figure 8. Extending upwardl from the slide is a projection I52 which has a plate I54 secured to it, the free end of the plate extending over the pusher I45. A compression spring 56 is located between the plate and the upper end of the pusher, and serves to urge the pusher downwardly to the position shown in Figure 8. The upper end of the pusher is provided with a bevelled surface I58 which is adapted to be engaged by the bevelled surfaces IIE) on the fork member I04 when the slide is moved to the right, as viewed in Figures 8 and 10, by the arm I32 on the lever I28. When such engagement takes place, the bevelled surface I58 will ride upwardly on the bevelled surfaces IIZI and will thereby cause the pusher to be lifted upwardly out of engagement with the nuts N in the chute, so that as the slide IIZ continues to move to the right, there will be no tendency for the pusher to move the nuts upwardly in the chute. The movement just described takes place as the punch member is moved downwardly. When this downward movement, and the punching operation which will be presently described, has been completed, the punch member moves upwardly and the arm I32 on lever I28 is thereupon moved to the left, as viewed in Figure 8. This permits the spring IE8, which has previously been compressed, to cause the slide H2 to likewise move to the left, and as it does so, the bevelled surface I58 on the pusher will slide downwardly on the bevelled surfaces I IS on the forked member, thereby allowing spring I58 to move the pusher downwardly so that its pointed edge 55:] engages the side of the nut N immediately below it in the chute, and as the slide IIZ continues to move to the left, the column of nuts in the chute is moved along therein so that the lowermost nut is fed out of the chute beneath the punch member, where it is held in position by the magnetic force set up by the permanent magnet 82 located within the punch member.

The first step in the operation of the method and machine, after the sheet metal member S has been located in the proper position under the punch, with its lower surface resting on top of the die member 33., is to operate the controls, which will be presently described, which will cause hydraulic pressure to be supplied to the cylinder Gil through passage I69. This will serve to move the piston 64, and the punch '54 which is secured to piston rod 66, downwardly with considerable force and since one of the nuts N is held on the lower end of the punch by the permanent magnet, the body portion 2 of the nut is driven through the sheet S, the metal being sheared between the sharp edge at the top of the: dies-around the square= hc1e--38 and the -edge-of the bodyx-portionyof theinut, andcthe piece of metal which is cut-out-ofthe sheet metal by thebody.'portion-lofatheinut serving as a punch dropping" downwardly-through the. hole 38 and out through the:dischargeiopeninglfi. At

this timethe nut -is:in the-position 'shownzin Figures2-4, i. e.,-the-body portionyi' of the nut extends through the hole it has punched; and'the flanges l bear against thesupper surface ofthe sheet, as best shown in Figured i The next operationservesfto' stakevthe nut in position i in the hole it has punched; so that it will be positively held therein. --.Thisis' accomplished by rotating .the female .die-:45' so that. the center portions -.of :itsfshe'aring edges, 42-wm extend diagonally-acrosszthe'corners of the body portion of the nut when it isbrought intonengagementwith xthe --latter;- and when pressureis 1 applied will serveto displace 'the' metal-in these i the nut is securely stalied in place in the'hole in the sheet metal.

'The female die.-is rotated .by' the-mechanism shown in Figures li-to '7. Mounted onitop of cyl-r inder 22 is a-housingifid, the upper endof which is closed by aicap Hiliythrough'which 'cap'the piston rod 28 extends. -Held" withinithei housing is a lower cammember was andxan uppercam member llii, which areiseparated from each other bya-spacencollar1:72; andiare'locked together by a key. FM. .The lower cam'rnernber is provided with a pluralityofispaced notches i it, which extend angularly around the space between thepiston' rcd 23 and .thespacer collar H2. Betweenithe notches: lflfiiihcli'ned cam'surfaces H8 are provided. 'Thexuppercarn member is likewisejprovided 'with'spaced'notches I 8E1 between-which are camsurfaces 1182, which are-inclined in theoppositedirection from the' am surfaces I18. V

Secured in the piston rod by' .a set" screw 18 is a pin I85, the projecting tends of-which are adapted to bereceived in thesnotches H6 and 180. Sincethe'pin-is secureduin the piston rod,

it moves up or down withithe latter as the piston '26 is moved up or down. "In Figures 4 to7, the

"ends of the pin i86xare shown lying-in two 'of the oppositely disposed notches "I80 in the upper 'cam member, since in'thosefigures the piston26', piston-rod '28 and female die34 are'shownin their uppermost position, in which they are held by hydraulic pressure supplied to the cylinder 22 through passage 188.

Immediately after'the punching operation has "taken place, the hydraulic "pressure: entering through passage I88 is'relievedg-and---pressure is supplied on the opposite side of 1 piston through passage I90, forcing-the piston "and piston rod downwardly. When pin lfifiengage's the inclined cam surfaces l18 ,-it-slides downwardly thereon and thereby c'auseslthe piston rod to be rotated in a clockwise direction -'-until the pin enters .as the ends of 'the. pin IBBengage' the cam surfaces I82 on the .upper 'cam memben theyslide upwardly over the latter, thereby causing the piston rod 28 to be rotated still further in a clockwise directiomuntil'the ends of-the pin come to restin a pair of notches I in the upper cam member, The amount of rotation during this up wward movement is likewise 22 and this added to the 22% which took place during the downward movemeht,'makes a total of-"45" rotation which takes place each time the female die is moved downwardly'and thenupwardly again by the piston 26 and piston rod'28.

Afterthe staking operation by-the female :die has been completed, I the latteris again moved *downwardly and then upwardly by piston 25, and since itagain is rotated 45 during these two -movements, it is now in a position where it has been rotatedSO from the position first described. In its present position, the sides of the square hole 38 will'be parallel to the sides of thebody portion of the nut-held immediately above it on the punch by the permanent magnet, so'tha't the female die is nowin proper position to-provide the cutting edges when the punch "descends again to force the body "portion ofthe-clinch nut through the sheet metal.

Immediately after the staking operation is completed, the'hydraulic pressurewhich has been holding the punch down so thatit may serve as an anvil during the stakingoperation, is relieved and pressureis admitted on the opposite side of the piston 26 through passagelB'I, thereby moving the punch upwardly and actuating the feeding mechanism to advance-anothernut into position under the punch "whereit isheld bythe permanent magnet.

It will be seen that every other time-the number 3d is at its upper limit of-' travel, the hole 38 in it is in such position relative to the body portion of'the nut immediately above-it'that it "is adapted to serve "as a femaIe die-to assist-in cutting out thepiece of them'etal sheet which must be removed to allow the nut body portion-to extend throughthe sheet, and that at the alternate times it is 'atits upper limit of'travel, it is turned 45 so thatthe'central portions of the side edges of the hole-3s extend diagonally-across the corners of the body portion in order that 'they'may serve to flatten or stake over these corners to lock thenut in position-in'the' metal sheet.

After this latteroperation has been completed,v the metal she et S- ismoved to another position where it is desired-to insert a clinch nut init,

and the operator actuates the starting control.

which causes the machine torepeat-the cycle of operations described above. In other'wcrds, all. that the operator has to do is to place the metal sheet in the proper position in'the' machine and. start the latter,- and thereafter 'the' sequence of T operations is automatically performed and when:

these are completed; the machine is shut off.

This automatic operation of the machine is brought about by the -folcwing structure. In Fig-- ure 12 there is-shown diagrammatically the piping and valves "which control the flow of hydraulicfpressure to the cylinders which producethe necessary sequence of m'ovements of-the punch i l and thefemale die member -34. [92' is a pump driven by an electric motor I94, the

inlet side of the pump being connected by a'pipe' I 96 to a fluid supply chamber 198, and theoutlet side by pipe Z-Ildto asolenoid"valve-designated. as SVI; which is a 'conventional raceway valve which is operated by an electrically actuatedsolenoid. Another pipe 202 leads from the outlet side of pump I92 back into chamber I98 to maintain a reduced amount of pressure in the latter.

At the beginning of the sequence of operations described above, when the operator actuates the starting control, the valve SVI is moved to a position wherein fluid pressure entering it through pipe 200 is permitted to flow out through pipe 204 which is connected to passage I88 in the cylinder 22. This forces piston 26 upwardly moving the female die member 34 to its uppermost position, in which position the metal sheet S rests upon it. At the end of this upward movement, the pressure built up in pipe 204 enters a pressure switch designated generally as PS2. This consists of a cylinder 206, one end of which is connected by pipe 208 to pipe 204, and containing a piston 2I0 to which is connected 2. switch contact member 2I2.

Passage I90 leading into cylinder 22 is connected by pipe 2I4 to valve SVI, and 2I6 is a pipe which conducts fluid returning through the valve SVI back into the supply chamber I98. Leading from pipe 2I4 into cylinder 2I8 of a pressure switch PS3 is a pipe 220, and 222 is a switch contact member which is actuated by piston 224 in this cylinder, when the fluid pressure within pipe 2I4 reaches its maximum.

Branching off from the pressure supply pipe 200 is a pipe 226 which leads into another fourway valve designated as SVZ, which is also solenoid operated. A pipe 228 conducts fluid pressure from this valve to passage I60 leading into cylinder 60 when the punch member 14 is to be forced downwardly. Pipe 230 leads from passage I81 in cylinder 60 to valve SV2, and 232 is a pipe through which fluid returning through the valve SVZ is conducted back into supply chamber I98.

A pressure switch designated as PSI is connected by pipe 234 with pipe 228 and is adapted to be actuated whenever the fluid pressure in the latter reaches its maximum, piston 236 in the cylinder 238 moving switch contact member 240.

Leading up from the fluid supply chamber I98 is a pipe 225 which is connected into cylinder 2I0 of pressure switch PS3. Branching off from pipe 225 are pipes 221 and 229, pipe 221 connecting into cylinder 206 of pressure switch PS2, and pipe 229 connecting into cylinder 238 of pressure switch PSI. Each of the pressure switches is returned to the position in which they are shown in Figure 12 by the fluid pressure supplied to them from the chamber I98 through pipes 225, 221 and 229.

In Figure 13 there is shown a wiring diagram of the electrical circuit which serves to control the flow of fluid pressure to the power cylinders 22 and 60, the solenoid valves SVI and SV2, and

the pressure switches PSI, PS2 and PS3 being shown diagrammatically in this figure, and the piping between these various members being broken away to clarify the drawing.

A suitable power source is provided, and as shown in Figure 13, the primary P of a transformer T is connected to this power source which in the apparatus being described is 440 volts. Conductors 24I and 243 lead a 110 volt circuit from the secondary S of the transformer. FBI and PBZ are push buttons and CRI is a relay which are connected by conductors 242, 244, 246 and 248 with the conductors 2M and 243. At the beginning of the sequence of operations of -,the machine, the upper contacts of both push buttons are closed, so that the winding of the relay CRI is energized and its contacts are closed. A parallel holding circuit is provided for the winding of the relay CRI, this holding circuit including the lower normally closed contacts of relay CRI and the normally closed upper contacts of the relay CR4 and the conductors 250, 252 and 254, the latter being connected to conductor 246.

To start the sequential operation of the power means, the operator is required to press both control buttons FBI and PB2. A the lower contacts of these push buttons and also the upper contacts of the relay CRI are connected in series by conductors 256, 258, 260, 262, 264 and 243 with the coil of relay CR2, this coil will be energized and all of its controls will close. It will be noted that the upper contacts of the relay CR2 are connected in series with the pressure switch PSI, the upper normally closed contacts of relay CR1 and the winding 265 of the valve SVI across the 440 volt primary power source indicated by the conductors 266 and 268 which are connected to the primary of the transformer. The above series connections comprise conductor 266, 210, 212, 214, 216, 218 and 268. This causes the energization of valve SVI to move the latter to a position wherein fluid pressure from the pump I 92 is allowed to flow through pipe 284 and passage I88 into cylinder 22, thereby moving the female die 34 to its upper position. As explained above, the metal sheet S rests upon this die, in proper position to receive a clinch nut at the desired location.

The simultaneous closure of the lower contacts of relay CR2 which are connected in serie with the lower contacts of relay CR1 by conductors 262 and 280 across the conductors 24I and 243 establishes a holding circuit for the winding of relay CR2. Simultaneous closure of the middle contacts of relay CR2 which are connected in series with conductors 266, 282, 284 and 286 sets up a circuit to these conductors. As the pressure in pipe 204 builds up, pressure switch PS2 is actuated. Its contacts are connected in series with the winding of relay CR3 by conductors 288, 290 and 292 across conductors 286 and 268. When the pressure is sufficient to close the contacts of switch PS2, the winding of the relay CR3 will be energized to cause closure of its contacts.

Closure of the lower contacts of relay CR3, which are connected in series with the winding of relay CR4 by conductors 294, 296, 298 and 300 across conductors 286 and 268, causes energization of the winding of relay CR4 thereby opening of the upper contacts and closure of the three lower contacts thereof. The opening of these upper contacts opens the above described holding circuit to the winding of the relay CRI and it will drop out. The closure of the contacts second from the top of relay CR4, which are connected in series to conductors 286 and 296 by conductor 302, establishes a holding circuit comprising conductors 286, 302, 296, 298, 300 and 268 for the winding of relay CR4.

It will be noted that the lower contacts of relay CR4 are connected in series with the central contacts of relay CR1 and the winding 30! of solenoid valve SVZ by conductors 282, 304 and 386 across conductors 266 and 268. When this circuit is closed, winding 30I is energized and valve SV2 is moved to a position wherein fluid pressure from the pump I92 is permitted to flow through pipe 228 and passage I60 into the top of cylinder 60, thereby forcing punch member 'ld ddwnwardly and-drivingthe bodyportion of;

the clinch nut' which is held on the lower side of: the punch member through the metal sheet,

as previously described. A

The contacts second from the bottom of relay CR4 are connected in series with the-normally open contacts of pressure switch PS3 and the winding of relay CR6 by conductors 308, am, 3 I 2,

3M and 3B6 across conductors ZBB-and 268. By

this'time sufficient pressure has been'built'up in pipe '228 :to cause pressure switch PS! to open andaccordingly deenergize coil 265 of valve SV'I,

which causes the-lattento move to a position 7 wherein the pressure in pipe :204 will be free to return to the supplychamber l98,'and pressure fromthe pump I 92 will be allowed to flow through pipeZIi-and. port IBO With-cyIinder 22, whichwillicause the female die 34 to move downwardly,

it:- being turned .22 /2"during this downward movement by the mechanism previously describedl At this time due to the pressure built up in ductors Subtle and 268 to the winding of relay CR6. The lower contacts of relay CR6 which arenowclosed are connected in series between the conductors 266 and 212'by conductor M8, and an. energizing circuit is completed through conductors 265, 8,114, 215, 218 and 268 to the winding 255 .of'valveSVI, causing'the latter to moveagain to position wherein fluid pressure from the pump will be permitted to flow through pipe 204 into the lower end of cylinder 22. causingthe female die to move upwardly again, during which upwardmovement it: Will-beturned another 22 /2", so that it now will have i been turned a total of 45 from the position it was in at the-com letion of the punching operation. As

it strikes the corners of-the body. portion of the nut at the end of its upward movementit forces the metal outwardlv, as previously described tohold the nutin position in the hole in the sheet metal.

The middle contacts of relav CR6 which are nowclosedare connected in series with the up er 'contactslof relay CR3. whichare open, and the winding of relay CR7 and across conductors 2% and'ZSt by conductors iiiiil," 32h and As aresult of the pressure which is now built in pipe 204', pressure switch PS2 closes again to cause reenergization and closure of relay CR8, 'whichresults in the energization of the winding 'of relay CR1 through conductors 285, 32s, 3222, 324, 326 and zts, and the'openin'gof all or its contactsz-a The opening of the upper contacts of rela'yi CR4 deenergizes winding. 265 of valve SVLY moving the latter to position-wherein the pressure inpipe 2M may .return to chamber its, and pressure from the pump is supplied through pipe zl i' to the upper part of cylinder 22. which causes the female die to movexdownwardly, beingturned 22 during such-movement.

The opening of the middle-contacts of relay' CR1 opens the circuit to windingrtlli of' valve SVZ, and the opening, of the lower contacts of relay CR1 opens the holding circuit of the winding of relay CR2. windingizw of valve -SVl', movingthe latterto position wherein the pressure in pipe 254 is al- This causes deenergization of lowed=to return to-chamber use, and pressure is supplied through'pipe-Eiito cylinder "22' to force female die 34 upwardly again, it being turned another 22 Z duringthis-"upward movement.- It is now-in its starting position again. At the same time, winding 30! of valve SVZ is deenergized, moving the latter toposition wherein thepressure within pipe 2236s allowed to return to the supply chamber, and pressure from the pump is permitted to flow through pipe 23% into the lower end of cylinder 38, thereby moving the punch member upwardly; during which upwardmovement the feedingmechanism is actuated to advance another clinch nut into position under the punch member, where it will be held'by the permanent magnet 82,-as previously described.-

At this time all'of the parts of the apparatus have been-returnedto'their starting position; and

the apparatus is ready-to commence another sequence of the operations described flbOV6,bill3 this will not take place until the operator again presses the starting buttons PB! and P132.

While a specificembodiment of my invention has been shown andde'scribed, it will be understood that variouschanges in practicing themethod and in the construction of the appara tus may be made without departing from the spirit and scope of the appended claims.

I claim:

1. The method of attaching a clinch nut having a non-circular body to a sheet of material, which comprises holding the nut on a punch member, suppor ing the sheet on a die member, moving the punch member toward the sheet whereby said body of the nut is driven through the sheetinto the die memberretractingand rotating the die member, and thereafter moving the die member into engagement with said nut to stake a portion of the body of the nut farthest fronr the axis of said nut.

2. The method of attaching a clinch nut having a non-circular bod portion to a sheet of material, which'comprises holding the nut ona punch member, forcing said body portion through the sheet into a hole in a die member, retracting the the die member, retracting the die member and atthe same time turning it to a difierent position; and then moving it toward the sheet, the edges of the die member forcibly engaging a portion of the body of the nut farthest from the axis of said nut to stake said portion.

4. In an-apparatus for attaching clinchnuts to sheet materiaL-the combination of a punch member, means associated with the punch member to-hold a clinchnut thereon, a die member having a'hole formed-therein, said punch member being movable toward the die member to force a portion of theclinch nut through the sheet material into the hole in said die member and means for reciprocating the die member toward 'and away from the nut in the sheet mate-' riaL'said die member being rotatable relative to" said nut while not -in engagement therewith to cause-the die member to contact said portion of" :the nut upon subsequent movement ofsaid die member toward said nut to stake the corners thereof against the sheet material.

5. In an apparatus for attaching clinch nuts to sheet material, the combination of a punch inember, means associated with the punch member to hold a clinch nut thereon, a die member having a hole formed therein, means connected to the punch member for driving said punch member downwardly to force a portion of the clinch nut through the sheet material into the hole in said die member, means connected to the die member for moving it downwardly and then upwardly, and means connected to the die member for rotating it a part of a revolution during such downward and upward movement to cause said die member to stake the corners of the body portion of the nut on its upward movement.

6, In an apparatus for attaching clinch nuts to sheet material, the combination of a punch member, means associated with the punch member to hold a clinch nut thereon, a die member located opposite said punch member, and means for rotating said die member to cause it to be adapted when in one position to cooperate with the punch member to force a portion of a clinch nut through the sheet material, and when turned to a different position being adapted to stake the corners of said portion of the clinch nut to hold the latter in position in the sheet material.

7. In an apparatus for attaching clinch nuts to sheet material, the combination of a punch member, means associated with the punch member to hold a clinch nut thereon, power means adapted to move said punch member toward the sheet whereby a portion of the nut will be driven through the sheet, a die member located opposite the punch member, power means adapted to retract said die member after the punching operation, means associated with said die member causing it to turn when retracted, the power means for operating said die member being also adapted to force the latter toward the sheet whereby the die member engages the corners of the portion of the nut which extends through the sheet to stake said corners, and control means adapted to control the sequential operation of said power means.

8. In an apparatus for attaching clinch nuts to sheet material, the combination of a punch member, means associated with the punch member to hold a clinch nut thereon, fluid pressure operated means adapted to move the punch member toward the sheet whereby a portion of the nut will be driven through the sheet, a die member located opposite the punch member, fluid pressure operated means adapted to retract said die member after the punching operation, means to turn said die member during the retracting movement, the last named fluid pressure operated means also serving to move the die member toward the sheet whereby the die member will engage the corners of the portion of the nut which extends through the sheet to stake said corners, valve means to control the flow of fluid pressure to said pressure operated means, and electrically actuated means serving to control the operation of said valves to produce the desired sequential operation of said pressure operated means.

9. The method of attaching a nut having a noncircular body portion and flanges extending therefrom to a sheet of material, which comprises forcing said body portion of the nut through the sheet and into a hole in a die memher to form an opening in the sheet, said portion remaining in the opening, retracting and rotating the die member, and thereafter forcibly engaging said nut with said die member to stake over a part of the body portion of the nut farthest from the axis of said nut.

10. In an apparatus for attaching a clinch nut to a sheet of material, a punch member having means associated therewith to hold a clinch nut, a die member having a hole formed therein, means for relatively reciprocating the die member and the punch member toward and away from each other, said members when moved toward one another being adapted to force a portion of the clinch nut through the sheet into the hole in the die member, and means for partially rotating said die'member and the nut in the sheet relative to each other when not in engagement to cause the die member to subsequently engage corners of the nut which extend through the sheet to stake over said corners.

11. In an apparatus for attaching clinch nuts to sheet material, the combination of a punch member, means connected to the punch member to hold a clinch nut thereon, a die member for supporting the sheet material and having a hole formed therein, means operatively connected to said die member and said punch member to cause said members to relatively move toward and away from each other, said members when moved toward one another being adapted to drive a portion of the clinch nut through the sheet material into the hole in the member, and means operatively connected to the die member for partially rotating said die member relative to the nut in said sheet when said die member and said nut are in spaced apart positions to thereby cause the die member to stake over said portion of the nut upon subsequent contact therewith.

12. In an apparatus for attaching clinch nuts to sheet material, the combination of a punch member, means connected to the punch member to hold a clinch nut thereon, means connected to said punch member for moving it toward the sheet whereby a portion of the nut will be driven through the sheet material, a die member located opposite the punch member, and means con nected to said die member for retracting and rotating it after the punching operation, the means for retracting the die member also being adapted to force said die member against the clinch nut to stake the corners of said portion of the nut to hold the latter in position in the sheet material.

LOUIS MUCHY.

References Cited in the file of this patent UNITED STATES PATENTS Great Britain Dec. 30, 1942 

